In the sector of dental implantology, when a patient has to have a biological dental piece replaced with an artificial dental implant, what first has to be done is to produce, by means of technical surgeries, a maxillary implant on which to secure the artificial dental implant. Therefore, the surgeon has to analyze the morphology of the maxillary of the patient in question in order to make bores in the bone, in which the maxillary implants are threaded. These maxillary implants consist of straight titanium or zirconium screws, equipped with an exterior thread and a hexagonal head in order to secure the same by means of threading to the bore made in the maxillary and with a concentric interior threading to secure the metal pillar and dental cover on the same.
Since the maxillary morphology is different for each patient, the surgeon inserts the implants at different inclinations as a function of the maxillary characteristics. Therefore, the lack of perpendicularity of the axial axes of the maxillary implants poses an alignment problem which must be solved by means of inserting aligned metal pillars of the dental covers angled for correct insertion in the assembly of the denture.
The metal pillars, both the straight and angled ones, are secured to the maxillary implant by means of a threaded screw, which passes through an axial orifice made in the metal pillar. In this way, the metal pillar is placed on the maxillary implant and the screw is tightened from the exterior by way of a shaft made in the upper base of the metal pillar. Once the metal pillar is positioned and tightened, the dental cover is put in place and is sealed so as it is immovable.
One of the drawbacks of dental implants of this type is that with time and the percussion with the mastication of the patient, the fixing screw becomes loosened, causing vibrations in the dental piece, with the consequent discomforts for the patient and even the detachment of the dental piece. Since the dental cover is sealed over the metal pillar, it is not possible to access the screw to tighten it, therefore it is necessary to break it in order to tighten it and put in place a new cover with the costs that this entails.
When the operation for tightening the screw of the metal pillar is carried out once again, deformations and limitations are observed, such as for example deformations of the hexagonal angles of the pillar; damage to the hexagonal head and the thread of the fixing screw of the pillar which cause loosening of the screw; an extremely weak screw, therefore the pressure of the adjustment thread is very limited.
Another drawback of this type of dental implant is that due to the reduced size of its components, such as the screw and hexagonal head of the implant, they become deformed, causing vibrations and the screw even breaks if it is tightened too much.